1. Field of the Invention. This invention relates to hydraulic torque wrenches, and more particularly to a flutter lift for disengaging a ratcheting pawl from a ratcheting gear during the return stroke of the hydraulic cylinder piston arm.
2. Prior Art. There is need for development of a hydraulic torque wrench which can withstand the large torquing forces necessary to loosen in-field bolts utilized on heavy industrial equipment.
Examples of the present state of the art can be seen in the following patents:
______________________________________ U.S. Pat. No. Inventor Issued Title ______________________________________ 3683686 Sergan 8/15/72 "Mechanical Torque Wrench and a Hydraulic Readout Therefor" 3745858 Birch 7/17/73 "Torquing Device" 3930776 Keller 1/06/76 "Hydraulic Wrench" 3995828 Orban 12/07/76 "Bolt Tensioning Device" 4027561 Jenkins 6/07/77 "Hydraulic Wrench 4060137 Bickford, 12/29/77 "Torque Wrench" et al 4091890 Wilmith, 5/30/78 "Very High Torque et al Ratchet Wrench" ______________________________________
Despite the prior art, there exists a continued need for hydraulic torque wrenches that more conveniently attach and operate in the field on equipment with less wear and tear. Also needed are torque wrenches which can more rapidly loosen and remove nuts from flange bolts. A particular problem with present hydraulic torque wrenches has been the breaking of ratchet gear teeth resulting from incomplete disengagement during the return stroke of the hydraulic piston arm. These problems are particularly acute in the petro-chemical industry and even more so on offshore drilling and pumping equipment where time saving means large savings in operating costs.